The use of Nitrile Butadiene Rubber NBR as seal in machines has increased in recent years. NBR is considered as the standard material for sealing and NBR owes its many applications to a range of special mechanical properties. However, the non-linear mechanical properties and incompressible behaviour of NBR make the analysis of NBR very difficult. The literature review highlighted the fact that the most common technical cause of hand pump failures was the wear of the piston seals. The contact surface of the piston seals with the bore surface (Brass) of the cylinder and the piston seal contact area are the key to calculating and determining seal friction force and seal wear rate. Several researchers carried out modelling of friction and wear processes, though little of these focused on the wear of NBR seals, and very limited research has been conducted on the wear of piston seals in the presence of water, and a very few has been reported regarding how to determined and calculating the wear rate of removal material of piston seals used in water hand pump.